I feel I was lucky to have a mentor as a skip-level manager who gave me the opportunity to explore the role before I dived into it and a manager who gave me active feedback during the transition. It's been 5 years since the switch, and I have grown to be DoE. I feel based on my experience that these are core to success in this role.
1. Managing downstream
2. Managing upstream
Downstream are what we all know as our teams and colleagues. During this transition, multiple challenges arise. Peers of yours become your reportees, your sense of technical correction to the team has to be balanced, you change from a guide to a mentor and, in some cases, to a coach as well, and your mindset changes from being a first-time problem solver to a long-term problem solver. Above all, your team needs to feel safe with you, which is the biggest success factor for you.
 
Upstream is very important, as it is your job: to ensure you communicate your team's genuine challenges and achievements, to look beyond the number of people reporting into you and rather how best you can resolve business problems, and to rightly reflect your TEAM'S successes and YOUR failures. In short, you need to acquire the skills of a skilled communicator and marketer.
 
A good read is The Manager's Path by Camille Fournier, and there are so many other resources nowadays, like Medium.com and blogs.
Something that helps with transition is listening to yourself in the beginning. As that voice gets lost, you entrench yourself, and it can become a case of faking it till you make it. My suggestion for this part is to always be honest with yourself at least and listen to your gut if days are getting better or worse with each passing timeframe.
 
I wish you all the best for the journey ahead.